1. Field of the Invention
The present invention relates to a display technology field, and more particularly to a liquid crystal display device and a GOA scanning circuit of the same.
2. Description of Related Art
A liquid crystal display device has many advantages such as thin size, saving power, and no radiation so that the liquid crystal display device has been widely applied. For example: the liquid crystal TV, the cell phone, the personal digital assistant (PDA), the digital camera, the computer screen, or the notebook screen. Accordingly, in the flat display field, the liquid crystal display device has a dominant position.
In the current market, the liquid crystal display is mainly a backlight type liquid crystal display including a liquid crystal display panel and a backlight module. An operation principle of the liquid crystal display panel is injecting liquid crystal molecules between a Thin-Film Transistor (TFT) array substrate and a color filter (CF) substrate, and applying a driving voltage on the two substrates to control rotation directions of the liquid crystal molecules in order to refract lights from a backlight module to generate a picture.
In an active liquid crystal display device, each pixel is electrically connected with one TFT. A gate of the TFT is connected with a horizontal scanning line, a drain of the TFT is connected with a vertical data line, and a source of the TFT is connected with a pixel electrode. When a sufficient voltage is applied on the horizontal scanning line, all of the TFTs connected with the same horizontal scanning line will be turned on such that signal voltages on the data lines can be written into the pixels, and controlling light transmittance of different liquid crystal molecules in order to control colors and brightnesses. The driving of the horizontal scanning lines of an active liquid crystal display panel is mainly achieved by an external integrated circuit (IC). The external IC can control the horizontal scanning lines to charge and discharge stage by stage.
A gate driver on array (GOA) technology is a row driving technology of an array substrate, which can utilize an original array manufacturing process of the liquid crystal display panel to fabricate the driving circuit of the horizontal scanning lines on a peripheral portion of a display region of a substrate so as to replace the external IC to finish the driving of the horizontal scanning lines. The GOA technology can reduce a bonding process of the external IC in order to increase production capacity and decrease the production cost. Besides, the GOA technology can make a liquid crystal display panel to be more suitable for a narrow-frame or a no-frame display product.
Generally, the GOA circuit includes following types: a GOA circuit based on P-type thin film transistors, a GOA circuit based on CMOS, and a GOA circuit based on N-type thin-film transistors. Wherein, the GOA circuit based on P-type thin film transistors, especially, the GOA circuit based on P-type thin film transistor made of a LTPS material has features of simple and low current leakage so that the development future is well. However, the conventional GOA scanning circuit having a bi-directional function requires more thin-film transistors and signal lines such that a non-effective display area is occupied more, which is not beneficial for a narrow-frame design or a no-frame design.